Tissue-specific and glucose-responsive expression of the pancreatic derived factor (PANDER) promoter
Tissue-specific and glucose-responsive expression of the pancreatic derived factor (PANDER) promoter
复制标题
DOI：
10.1016/j.bbaexp.2005.07.003
复制
发表时间：
2005-09-25
期刊：
影响因子：
--
通讯作者：
Wolf, BA
中科院分区：
文献类型：
--
作者：
Burkhardt, BR;Yang, MC;Wolf, BA
胰腺衍生因子（PANDER）是最近发现的一种主要表达于胰腺胰岛的类胰蛋白酶蛋白。为了研究PANDER的组织特异性调控机制，我们鉴定并表征了启动子区域。通过5 '-RLM-RACE鉴定转录起始位点在翻译起始密码子上游520 bp处。计算机算法确定了几个胰岛相关和葡萄糖响应性结合基序，包括A和E盒，肝细胞核因子I和4，Oct-1，信号转导和转录激活因子3和5。报告基因分析揭示了胰岛和肝源性细胞系中细胞类型特异性PANDER启动子的表达。PANDER mRNA水平与观察到的细胞类型特异性PANDER启动子基因表达直接一致。将最小元件定位到5 '-UTR，并且相对于转录起始位点位于+200和+491之间，并赋予最大基因表达。此外，几个假定的葡萄糖反应结合位点进一步功能特征，揭示关键的PANDER调控元件。PANDER启动子在鼠胰岛素瘤β-TC 3细胞和原代鼠胰岛中被证明是以剂量依赖性方式的葡萄糖响应性的，但在胰高血糖素分泌α-TC 3细胞中不响应。我们的研究结果表明，PANDER的5 '-UTR包含基因表达的最小元件，并赋予组织特异性和葡萄糖反应性。PANDER基因表达的调节模拟胰岛素的调节，提示PANDER参与代谢稳态的潜在生物学功能。(c)2005 Elsevier B. V.保留所有权利。
Pancreatic derived factor (PANDER) is a recently identified cytokine-like protein that is dominantly expressed in the islets of Langerhans of the pancreas. To investigate the mechanism of tissue-specific regulation of PANDER, we identified and characterized the promoter region. The transcriptional start site was identified 520 bp upstream of the translational start codon by 5'-RLM-RACE. Computer algorithms identified several islet-associated and glucose-responsive binding motifs that included A and E boxes, hepatocyte nuclear factors I and 4, Oct-1, and signal transducer and activator of transcription 3, and 5. Reporter gene analysis revealed cell type-specific PANDER promoter expression in islet and liver-derived cell lines. Levels of PANDER mRNA were directly concordant to the observed cell type-specific PANDER promoter gene expression. The minimal element was mapped to the 5'-UTR and located between +200 and +491 relative to the transcriptional start site and imparted maximal gene expression. In addition, several putative glucose-responsive binding sites were further functionally characterized to reveal critical regulatory elements of PANDER. The PANDER promoter was demonstrated to be glucose-responsive in a dose-dependant manner in murine insulinoma beta-TC3 cells and primary murine islets, but unresponsive in glucagon-secreting alpha-TC3 cells. Our findings revealed that the 5'-UTR of PANDER contains the minimal element for gene expression and imparts both tissue-specificity and glucose-responsiveness. The regulation of PANDER gene expression mimics that of insulin and suggests a potential biological function of PANDER involved in metabolic homeostasis. (c) 2005 Elsevier B.V. All rights reserved.